Photographic developer for color photography



55 general formula:

Patented Apr. 9, 1940 UNITED STATES PHOTOGRAPHIC DEVELOPER 'iFOR COLOR PHOTOGRAPHY Willard D. Peterson, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application September 23, 1938, Serial No. 231,382

9 Claims.

This invention relates to photographic developers and particularly to a new class of developers containing heterocyclic ring systems and adapted for use in various processes of color photography. V In the processes of color photography in which a colored image is formed in a photographic layer by a color-forming development in which the development product of the photographic developer combines with a coupler compound, special types of developing agents must be used. The developing agents suitable for this purpose must contain a primary amino group and such developers are usually chosen from the classes of p-phenylene diamines and p-amino phenols or their various substitution products. described in the U. S. 1,l02,028,"June 30, 1914.

The choice of developer of these classesis somewhat limited and for this reason developing agents having suitable characteristics cannot always be chosen. For example, the use of thep-phenylene diamines is somewhat limited on account of their insolubility in the developing solution. When an attempt is made to introducesolubiiizing groups into these developers, valuable properties, such as'the color of the dye generated, are sometimes destroyed, and in the case of the p-amino phenol developers, the compounds are 0 frequently too soluble for color processes inwhich patent to Fischer No.

it is desired to form an insoluble dye image.

With both the p-phenylene diamine and p-amino phenol developers, the number and kind of substituents which may be introduced into the molecule is, of course, limited. It is, therefore, an object of the present 'invention to provide a new class of photographic developers particularly adapted'for color-forming processes. A further object is to provide a m class of photographic developers having suitable solubility properties and which form insoluble and stable-dyes bycoupling with color-forming compounds. A still further object is to provide a class of photographic developers which develop av 45 color image at an optimum rate. A still further object is to provide a class of velopers which penetrate the gelatin of the photographic layerin a sufiiciently short time to make them practical for photographic use. Other ob- 50 'jects will appear from the following description of myinvention. These objects are accomplished by the use of photographic developers containing a nitrogenheterocyclic ring ystem and having the following A process of this type is;

Photographic dea (01. ss- -ss) in which R. represents the atoms necessary to complete a heterocyclic ring system, and X is an alkyl}: hydroxyalkyl, or an allyl group.

In the above formula, R may be one of the following groups:

CH1 [CH NH CH1v 0 7 (3H) 1 I I Jam. 011, OH: CH: letihydro- Indoline Tetrahydro- 'letrahydro- Phenmorquinoline quinoxaline' quinazolme I pholine v X in which X is an alkyl, hydroxyalkyl, or an allyl group. v

Specific compounds which may, be used as developers according to my invention are the following, it being understood that these are exemplary only, and that they may contain other substituent groups as well as those included in these formulae:

, I CH NH on, i 41112 C PCHQOH Q 0 NH on, I 7 $13.:

l'-1nethyI-6-amino-l 3,3,4- tetrahydroquinoline l allyl -6 -amino l,2,3,4

tetrahydroquinoline N(fl-hydroxye thyl)-6-amino- 1,2,3,4-tetrahydroquinoline 1 p -hydroxypropyl) -6 amino-phenmorpholine l,3-dimet l-o-aminm l,2 ,3,4- t traliydrogulnoxalinc An important feature of the compounds used as developers, according to my invention, is the substituent group on the heterocyclic nitrogen atom of the developer molecule. This group in many cases has the property of increasing the solubility of the developing compound and also aids in the formation of a colored image when the photographic layer is developed in the presence of a coupler compound. I have found that developing agents of the type described above, when used in the presence of a coupler compound, do not produce a colored image if the developing molecule does not contain a substituent group in this position. The substituent groups attached to the heterocyclic nitrogen atom therefore possess a critical and importantfunction in the production of a colored image.

According to my invention a gelatino-silver halide emulsion layer, after exposure, is developed in'a solution containing as the developing agents one of the compounds described above. The solution may contain in addition a coupler compound, or the coupler compound may be present in the sensitive layer prior to exposure. The layer may be developed to a colored negative image directly or may be developed first to a black and white negative by development in the ordinary way and then developed in the coupler developer to produce a positive colored image. The silver is then removed from the film leaving a pure dye image.

The following example, which is illustrative only, indicates a method of developing a'colored image, according to my invention.

A gelatino-silver halide emulsion layer was exposed behind a steptablet, developed in a metolhydroquinone developer, washed, exposed to white light, and then developed for ten minutes at 70 F. in the following developer solutioni Developer grams 1.5 Sodium sulfite do 2.0 Sodium carbonate do 50. Potassium bromide do 2. Coupler do 2. Sodium hydroxide do 1. Water to c.c 100 -U. S. Patent 1,969,479, the hydroxydiphenyls Of Mannes and,Godowsky U. S. Patent No. 2,039,730, the aceto-or cyano-acetamides of Mannes and Godowsky U. S. Patent No. 2,108,602, the acetyl or benzoyl acetones of Mannes and Godowsh U. S. Patent No. 2,113,330, the cyanoa'cetyl compounds'of Mannes, Godowsky and Peterson U. 8. Patent No. 2,115,394, and the hydroxy styryl compounds of Marines, Godowsky and Peterson No; 2,126,337. V Specific coupler compounds which I have found suitable are the following:

To produce blue or blue-green dyes, o-cresol,

thymol, o-phenylphenol. 4-chloro 2-phenylphenol, 2,4-dichloro-B-naphthol; .to produce red or magenta dyes, 1-phenyl-3-methyl-5-pyrazolone and 2-naphthoylacetonitrile; to produce yellow or orange dyes, acetoacet-2,5-dichloroanilide and 76 w-benzoylacetanilide.

The compounds described above may be used to produce a colored photographic image in a single photographic layer or may be used to produce a natural colored image in a multi-color layer or may be used for any of the dye images produced in a multi-layer film by coupler development.

The compounds used as developing agents, according to my invention, are made in various ways. For example, the compounds N(p-hydroxyethyl) 6-amino-1,2,3,4-tetrahydroquinoline and 1- (p-hydroxypropyl) -6-amino-phenmorpholine are made as follows:

N (5-hydroxyethyl) 1,2,3,4 tetrahydroquinoline is prepared by the action of 1 part by weight of ethylene oxide upon 2 parts of 1,2,3,4-tetrahydroquinoline in a bomb (100-'160 C.) for four to nine hours. The resulting N(fi-hydroxyethyl)- 1,2,3,4-tetrahydroquinoline is purified by rectification and boils at 190-195 C./15 mm.

The N(fl-hydroxyethyl) -6-amino-1,2,3,'4-tetrahydroquinoline is prepared by nitrosating the foregoing product by adding dropwise the calculated quantity of an aqueous solution of sodium nitrite to an excess of chilled-17% hydrochloric acid solution of the product. The resulting nitroso compound is reduced by the slow addition of zinc dust, the end of the reduction being determined by the decolorization of the solution. The zinc sludge is filtered, the filtrate made strongly basic and the amino derivative extracted with amyl alcohol. The i-(p-hydroxyethyl) -6-amino- 1,2,3,4-tetrahydroquinoline is obtained by rectification and boils at 208-215 D./4 mm.

Phenmorpholine is readily prepared by the ac-' tion of ethylene-chlorohydrin on ortho-aminophenol according to the equations:

on on +c1omcmon NH, NHCHICHzOH With propylene oxide the N-(B hydroxypropyl) group is introduced and upon nitrosation and subsequent reduction the desired G-amino derivative isobtained. I g

The developers used according to my invention may contain other substituent groups and other heterocyclic groupings than those speciflcally listed in the present specification. The examples given are illustrative only and other modifications may be made within the scope of the appended claims.

WhatIclaimis:

1. A photographic developer comprising a com pound of the general formula.

in which X is selected from the class consisting of alkyl, hydroxyalkyl, and allyl groups, and R represents the atoms necessary to complete-a heterocyclic ring.

2. A photographic developer comprising a 6- amino- 1,2,3,4-tetrahydroquinoline having on the heterocyclic nitrogen atom a substituent selected from the class consisting of alkyl, hydroxyalkyl, and allyl groups.

3. A photographic developing solution comprising a developing agent of the general formula l I I f' X l in which X is selected from the class consisting of alkyl, hydroxyalkyl, and allyl groups, and R represents the atoms necessary to complete a heterocyclic ring, and a coupling. compound which combines with the oxidation product of the developing agent on'photographic development to produce a colored image.

4. A photographic developing solution comprising as a developing agent a 6-amino-1,2,3,4- tetrahydroquinoline having on the heterocyclic nitrogen atom a substituent selected from the class of alkyl, hydroxyalkyl, and allyl groups,

and, as a coupling agent. a compound which combines with the oxidation product of the developing agent on photographic development to produce a colored image.

prising as a developing agent a 6-amino-l,2,3,4- 10 tetrahydroquinoline having a hydroxyalkyl substituent on the heterocyclicnitrogen atom, and as a coupling agent, a compound which combines with the oxidation product of the developing agent on photographic development to produce a colored image; y

7. A photographic developing solution comprising as a developing agent a 6-amino-l,2,3,4- tetrahydroquinoline having as allyl substituent on the heterocyclic nitrogen atom, and as a coupling agent, a compound which combines with 1 the oxidation product of the developing agent on photographic development to produce a colored image.

8. The method of producing a colored photo-- graphic image in a gelatino-silver halide emulsion layer, which comprises coupling the devel-' opment product of a B-amino-1,2,3,4-tetrahydroquinoline having on the heterocyclic nitrogen atom a substituent selected from the class consisting of alkyl, hydroxyalkyl, and allyl groups,

with a phenolic coupler compound.

9. The method of producing a colored photographic image in a gelatino-silver halide emulsion layer, which comprises coupling the development product of a G-amino-l,2,3,4-tetrahydroquinoline having on the heterocyclic nitrogen atom a substituent selected from the class consisting of alkyl, hydroxyalkyl', and allylgroups,

with an acetamide coupler compound.

' wmmnn n. ra'mason. 

